壳聚糖-泊洛沙姆为凝胶基质的纳米银抗菌凝胶的制备与表征

Preparation and Characterization of Chitosan-Poloxamer-based Antibacterial Hydrogel Containing Silver Nanoparticles

为了解决当前纳米银抗菌凝胶体外细胞毒性大、用光引发法制备纳米银时其颗粒尺寸和尺寸分布范围大的问题，本研究采用了物理交联法制备壳聚糖凝胶，由于采用泊洛沙姆作为制备纳米银的分散剂，制备出生物相容性更好且抗菌效果良好的纳米银抗菌凝胶。本研究加入泊洛沙姆作为纳米银分散剂以光引发法制备纳米银，并对制备的纳米银混合液与烘干后颗粒分别进行紫外可见吸收光谱实验和扫描电镜（SEM）实验。研究采用以碳酸氢钠对凝胶pH值进行调节的方法形成凝胶，并对其进行pH值测试、凝胶断面的SEM测试、溶胀率测试、黏度测试、抑菌圈实验以及体外细胞毒性实验。测试结果显示，当以超纯水为溶剂时，以泊洛沙姆为分散剂所制备出的纳米银的最大吸收波长为414 nm，平均粒径约为60 nm，相比于以聚乙烯吡咯烷酮（PVP）为分散剂或以蒸馏水为溶剂时所制备出的纳米银具有更小的粒径以及更窄的粒径分布。所制备出的凝胶的pH值介于5.8～6.1之间，呈弱酸性。干燥后的凝胶断面具有较多孔洞，凝胶的吸水性良好，且黏度适宜，易于涂布于纱布上。此外，所制备出的凝胶在24、18、12 μg/mL的纳米银浓度下具有较好的抑制大肠杆菌与金黄色葡萄球菌的能力，且在纳米银浓度为24 μg/mL以下时均具有良好的生物相容性。基于以上特性，该纳米银抗菌凝胶有望应用于烧创伤口的治疗。

In order to solve the problem of high cytotoxicity in vitro of nano-silver antibacterial gel, and the problem of large nano-silver particle size and size distribution, this study prepared nano-silver antibacterial gel with better biocompatibility and good antibacterial effect by using physical cross-linking method and using poloxamer as dispersant when prepared nano-silver. In this study, nano-silver was prepared by photo-initiator method and by adding poloxamer as a dispersant, and then UV-visible absorption spectrum test and scanning electron microscopy （SEM） test were carried out using prepared nano-silver mixture and particles after drying respectively. The gel was prepared through adjusting its pH value by using sodium bicarbonate, and then pH value test, SEM test for cross-section of gel, swelling ratio test, viscosity test, inhibition zone test and in vitro cytotoxicity test were carried out. The test results showed that the maximum absorption wavelength of prepared nano-silver, using poloxamer as dispersant and ultra-pure water as solvent, was 414 nm, and the average nano-silver size was about 60 nm. The prepared nano-silver using poloxamer as dispersant had smaller particle diameter and narrower particle size distribution than those using PVP as dispersant. Similarly, the prepared nano-silver using ultra-pure water as solvent also had smaller particle diameter and narrower particle size distribution than those using distilled water as solvent. The pH value of the prepared gel was between 5.8～6.1. The dried gel section had many holes. The water absorption of gel was fine and the viscosity of gel was fit to coat on the gauze. In addition, the prepared gel with nano-silver had greater ability to inhibit Escherichia coli and Staphyloccocus aureus at the concentrations of 24, 18 and 12 μg/mL. And the biocompatibility of the prepared gel with nano-silver was good when the concentration below 24 μg/mL. Based on the above features, the nano-silver antibacterial gel could be used in the treatment of burn or other wounds.